Improvement in metal-turning lathes



7 23h --Sh 1. JOHN w. HYATT, Jr.

Improvement in Metal Turning Lathes. No. 125,571, y; PatentedApril9,1872.

2 Sheets--Sheet '2.

JOHN W. HYATT, Jr. Improvement in Metal Turn ing Lathes. N0.125,5 71.

Patented April 9, 1872.

1 ."NI'IED STATES PATENT, CF FIGE.

JOHN W. HYATT, JR, OF ALBANY, NEW YORK, ASSIGNOR OF ONE-HALF HIS RIGHT TO HUGH W. OOLLENDER, OF NEW YORK CITY.

IMPROVEMENT IN METAL-TURNING LATHES.

Specification forming part of Letters Patent No. 125,571, dated April 9, 1872.

SPECIFICATION.

I, JOHN W. HYATT, J r., of the city and county of Albany, in the State of New York, have invented certain Improvements .in Spherical Lathes, of which the following is a specification:

My improvements relate to that class of lathes which are used for turning spherical bodies, and in which the piece to be turned is clamped between two heads or mandrels.

In turning spherical bodies it is essential that the pivot-pin of the tool-rest shall maintain a position vertically beneath the center of the article to be turned. Previous to my invention, only one of the heads being longitudinal] y adjustable, (as the article became turned down so as to lessen its diameter,) the tool-rest was required to be adjusted laterally in order to maintain the proper position of its pivot under the center of the article being turned. Considerable labor and care was necessarily required to effect an accurate and proper adjustment of these parts.

My invention consists, first, in the combination, in a lathe, and with a pivoted tool-rest and two heads or mandrels, of a screw-shaft, which connects, by suitable means, with the two heads, or with one of the heads and toolrest, so as to cause the parts so connected to be simultaneously adjusted by turning the said screw-shaft, whereby the tool-rest is maintained in its proper relative position equidistant from two heads, as hereinafter more fully set forth; second, in the combination and arrangement, in a lathe, with the bed-plate, pivoted tool-rest, and the two revolving heads or mandrels, of a screw-shaft and two followers connecting the ends of said screw-shaft with the revolving mandrels, so that by turning of the screw-shaft the mandrels will be made to simultaneously approach or recede from each I other with uniform speed; third, of the baseplate of the tool-rest provided with a beveled edge, arranged with conical-pointed screws working through suitable heads or bearings screwed into the bed-plate of the machine, by which the said base-plate is secured to'the latter and adjusted thereon.

In the accompanying drawing, consisting of two sheets, Figure I is a longitudinal elevation of my improved lathe. Fig. II is a plan view of the same. Fig. III is a plan. view, representing a modified form of my improved lathe. Fig. IV is a partly-sectional elevation; and Fig. V an end view of a lathe in which one of the heads and the tool-rest are adjustable. Fig. VI is a detached sectional elevation, and Fig. VII a plan view of the tool-rest. Fig. VIII is a section on line as m, Fig. III. Fig. IX is a fragmentary section on line 3 y, Fig. III.

Like letters designate like parts in each of the figures.

In Figs. I, II, VI, and VII, A represents the bed-plate of the lathe, and a a a a the headstocks or bearings, cast or otherwise secured to the upper side thereof. B B are two mandrels or clamping-heads, supported in the bearings a a, respectively, in such manner that they can slide longitudinally therein. One or both of these mandrels carry a pulley, b, to which power is applied by means of an endless band from the driving-shaft, the latter being arranged as usual with such machines. 0 is a shaft, arranged longitudinally under the bed-plate A, and supported in bearings c 0 cast with the latter. The ends 0 c of this shaft project beyond the bed-plate, and are provided one with a right-hand and the other one with a left-hand screw-thread of equal pitch.

This shaft is retained against longitudinal displacement by screw-nuts or collars d5 d, and operated by means of a hand-crank, d D D are two followers, connecting the ends 0 c of the shaft G with the mandrels B B. Their lower ends are perforated and provided with internal screw-threads corresponding with the threads on the end of the shaft 0 engaging with such follower. Their upper ends are provided with suitable sockets for the reception of the exterior ends of the mandrels B B. d is an annular groove turned in the end of each mandrel, and engaging with a pin secured in the socket of the follower for coupling the parts together, while the mandrel is left free to rotate. E is the base-plate of the tool-rest, and F thetool-rest proper, carrying the tool-holder f. The tool-rest F is connected to the baseplate E by means of a central pivot-pin, e, and

a circular dove-tail groove and feather, e, in such manner that it can freely turn on said base-plate. The circular edge of the latter is beveled off, as shown at g. Figs. VI and VII G represents set-screws, passing horizontally through lugs or bearings H screwed into the bed-plate A. Their ends, engaging with the base-plate E, are made conical, so as to correspond with the beveled edge 9 thereof, thereby securing the base-plate E firmly to the bed-plate A, and enabling the same to be readily adjusted laterally on the latter.

The tool-rest being so. adjusted on the bedplate A of the lathe that its pivot-pin assumes a position centrally between the two mandrels B B ,7 and vertically beneathflthe center of the article clamped, it remains stationary between the same during the operation of theturning, while the mandrels are adjusted simultaneously as the article is turned down. By turning the shaft 0 in one or the other direction the mandrels are made to approach or reoede fromeach other with the same speed, so that their faces remain in all positions equally distant from the pivot-pin of the tool-rest. Hence spheres of various sizes may be clamped between the mandrels B B, and their centers will always occupy a position perpendicularly over the center of the tool-rest, which is essential in the production of a perfect sphere.

In Figs. III, VIII, and IX is represented a modified arrangement by which the same purpose is accomplished.

A represents the bedplate. J is the live-spindle, carrying a pulley, j, and being supported in bearings I. K 'is the tool-rest, attached to the bed-plate A,

as hereinbefore described. L is a screw-shaft, arranged in line with the live-spindle J, and working through a bearing, 1, provided with an internal screw-thread. This screw-shaft is provided with two kinds of screw-threads, the

portion l working through the bearing I, having a thread twice as fine as the portion 1 as indicated in the drawing. The head of the spindle J is formed by a sleeve, on, revolving with the spindle by means of a feather, m, and capable of slidinglongitudinally thereon.

. N is a U-shaped yoke, connecting the sleeve --and fitting in a socket in the yoke.

The operation of this device is as follows:

By turning the screw-shaft L a rectilinear movement of the same toward or from the tool-rest is produced, and the same amount of movement in the opposite direction is produced in the sleeve m by virtue of the peculiar arrangement of the screw-threads on the screw-shaft L. Hence the latter and the sleeve m are caused, by these means, to approach and recede from each other with the same speed, insuring for the tool-rest at all times a position centrally between the heads clamping the piece to be turned.

In Figs. IV and V is represented a lathe in which one spindle is supported in fixed bearin gs, while the tool-rest and the second spindle are adjusted simultaneously with reference to the first one. B is the bed-plate; p, a spindle or mandrel, supported in fixed bearings 12*,- and carrying a pulley p Qisa head-stock,

carrying the-spindle or mandrel q, preferably provided with a pulley, q. Neither of these spindles is capable of longitudinal movement in its bearings. The head-stock Q slides in (love-tail ways R arranged in the direction of the mandrels p and q, and formed partly in the bed-plates and partly by a metal strip, '1". S is the tool-rest, constructed in the manner hereinbefore described. It is secured to a bedpiece, 8, also sliding in the dovetail ways It. T is a screw-shaft, working through the headstock Q and the bed-piece s of the tool-rest. It is operated by a hand-cranlgt, and retained against longitudinal displacement by a pin, 29, engaging in an annular groove provided in the screw-shaft. The portion t of the latter, operating the head-stock Q, is provided with a screw-thread having twice the pitch of the thread provided on the portion t which operates the tool-rest.

By turning the screw-shaft T the rectilinear movement imparted to the head-stock Q will be twice as fast as that imparted to the toolrest consequently the center of the tool-rest will at all times retain a position centrally between the stationary spindle p and the adjustable spindle q.

I claim as my invention- 1. The combination, in a lathe, and with a pivoted tool-rest and two heads or mandrels,

of a screw-shaft, which connects with two of rest, of the screw-bearings H and conicalpointed set-screws G, substantially as and for the purpose hereinbefore set forth,

JOHN W. HYATT, JR. Witnesses:

D. UADY HERRICK, W. S. HEVENOR. 

